In general, moving conditions of a mobile platform are detected using sensors that usually are detection device adopting means of encoding, light beam, locality, acceleration, and so on.
Among those detection methods for detecting moving conditions of a mobile platform, encoding by rotary encoders is the most commonly practiced. By mounting rotary encoders on wheel shafts of a mobile platform, physical quantities relating to the moving conditions of the mobile platform, such as position, velocity, angular position, angular velocity, etc., can be obtained and calculated from the detection of rotation difference of wheel shafts. However, the calculation of the mobile platform's moving conditions is based on the geometric of the mechanism of the mobile platform, which is easily affected by certain external factors. For instance, wheel slippery might cause enormous error in the calculation. Therefore, constant calibration is required while applying rotary encoder for detecting moving conditions of a mobile platform.
As for the method adopting light beam as the optical means for detecting moving conditions of a mobile platform, it is usually accomplished by mounting light emitters and light receivers on the mobile platform. In general, the light beam used in the foregoing optical method can be laser ray or infrared ray. It is known that the optical method is capable of detecting the distance between the mobile platform and a target object, and also the velocity of the mobile platform. However, when it comes to the detection of the absolute position of the mobile platform, other types of sensor are required for assisting the detection of the optical method.
Conventionally, the locality of a mobile platform is estimated and measured by electrical compass or inertial meter, and so on. However, such devices like electrical compass are only good for detecting the rotation of the mobile platform. Moreover, although devices like accelerometers can be used for detecting moving conditions of the mobile platform, the moving conditions of position and velocity can not be acquired directly, but will require to perform calculations of second order integration and first order integration on the detection result that is more than likely to cause more detection error.
In view of the above description, it is needed to have a mobile robot platform and a method for sensing movement of the same, which are capable of simultaneously detecting the physical quantities of the platform, such as position, velocity, angular position and angular velocity, etc, such that not only the accuracy of the detection can be increase while reducing error caused by all kinds of possible factors, but also the complexity of applying the method can be reduced.